Intact Tendon Research Articles

The fate of hypoechoic cleft

BackgroundHypoechoic clefts are small defects found on ultrasonographs in the intact rotator cuff tendon after rotator cuff repair. Little is known about the fate of these hypoechoic clefts, as to whether they will heal, persist, or develop into a retear.MethodsThis prospective study involved 24 patients who underwent arthroscopic rotator cuff repair surgery and were found to have a hypoechoic cleft at the 6-month postoperative ultrasonograph. A subsequent ultrasonography follow-up was performed at 9 months or later by the same ultrasonographer and the repair re-examined.ResultsAt an average postoperative follow-up of 21 months, 14 of the 25 hypoechoic clefts (56%) had healed; 5 (20%) had persistent clefts whereas 6 (24%) had progressed to a full-thickness rotator cuff retear. Patients with a hypoechoic cleft ≥36 mm2 were 5 times more likely to have a retear than patients with hypoechoic cleft <36 mm2 (relative risk = 5.1; P < .05). Patients with hypoechoic clefts ≥36 mm2 had a higher frequency of pain during activity and sleep and a lower level of satisfaction at the 21-month follow-up compared to those with small hypoechoic clefts (P = .05).ConclusionThis is the first study to evaluate the natural history of a hypoechoic cleft found at ultrasonography following rotator cuff repair. The study showed that clefts less than 36 mm2 are likely to heal, while those greater than 36 mm2 are at high risk of progressing to full-thickness retears.

The clinical and radiologic outcome of microfracture on arthroscopic repair for full-thickness rotator cuff tear

The persistent incidence of retear despite improvements in techniques led orthopedic surgeons to the application of principles of tissue bioengineering to achieve enhanced repair and functional outcomes. The purpose of this study was to compare clinical and radiologicoutcomes of arthroscopic single-row repair augmented with microfracture (SRM) at the greater tuberosity with single-row (SR) and double-row (DR) repair in the treatment of full-thickness rotator cuff tears. This is a retrospective comparative study. A total of 123 patients were enrolled for arthroscopic repair of full-thickness rotator cuff tears, with 40 patients treated by SR, 44 by SRM, and 39 by DR. The minimum follow-up was 2 years. The primary outcome was retear rate, which was detected by magnetic resonance imaging, and the secondary outcome was functional outcome. The mean age of the patients was 59.2 years, 58.1 years, and 60.6 years in the SR, SRM, and DR groups, respectively. The retear rate was 33%, 14%, and 36% in the SR, SRM, and DR groups, respectively(P = .045). The SRM group had significantly improved functional outcomes compared with the SR and DR groups in terms of the postoperative Constant score and visual analog scale score (P = .001 and .002, respectively). Delta Constant scores were nonsignificant for retear and intact tendons(P = .137). SRM has a significantly lower retear rate and better functional outcome than SR and DR repair.

Evaluation of hollow mesh augmentation on the biomechanical properties of the flexor tendon repaired with modified Kessler technique

PurposeThe aim of the study was to test flexor tendon repair with a novel hollow mesh suture augmentation served as a centre core cable [Triple-C (Tri-C)] in an in vitro study using a turkey model. MethodsForty long digits from white turkey feet were divided into the following four groups based on repair techniques: Group 0, intact tendon without repair; Group 1, modified Kessler (MK) repair only (MKo); Group 2, MK repair plus Tri-C (MK ​+ ​Tri-C); and Group 3, MK repair plus an additional outside knot plus Tri-C (MK-2knots ​+ ​Tri-C). Mechanical evaluations were performed for all groups. ResultsThe frictions of the two groups with Tri-C were not significantly different than those of the MKo group. The ultimate tensile strength of the MK ​+ ​Tri-C group was not significantly different from that of the MKo group or the MK-2knots ​+ ​Tri-C group. In contrast, the MK-2knots ​+ ​Tri-C group had a significantly greater ultimate tensile strength compared with that of the MKo group. Forces at 2-mm gap formation in the groups with Tri-C were significantly stronger than that of MK alone. ConclusionOur data have demonstrated that MK repair augmented with the centre hollow mesh suture increased failure strength without inducing increased friction. The translational potential of this articleOur study elucidates that a Tri-C augmentation designed in this study can achieve mechanical enhancements without increasing the repaired tendon friction. Hence, this novel technique has potential biological validity and clinical application.

Thumb Carpometacarpal Arthroplasty with Dynamic Suspension Sling Using Extensor Carpi Radialis Tendon.

Background: Despite various treatment methods, complications are reported with ligament reconstruction for thumb carpometacarpal (CMC) arthropathy, such as proximal migration, dorsal subluxation of the first metacarpal base, and hyperextension of the first CMC joint. The flexor carpi radialis (FCR) tendon is, in some cases, too thin to maintain suspension on the first metacarpophalangeal (MCP) joint. We used one-half of the extensor carpi radialis longus (ECRL) tendon instead of the FCR tendon, and compared this method with conventional reconstruction using the FCR tendon. Methods: The procedures were performed during 12 thumb CMC arthropathies. One-half of the ECRL tendon was passed and then wrapped around the intact FCR tendon several times for 6 cases (ECRL group). One-half of the FCR tendon was passed for 6 cases (FCR group). On radiography, we compared the thumb to index finger metacarpal angle (M1M2) and the first MCP angle (P1M1) between groups. Grip strength, pinch strength, and DASH score were also evaluated up to 2 years post-surgery. Results: In the ECRL group, M1M2 and P1M1 1 year post-surgery showed significant improvements compared to those before surgery; they showed no significant difference in the FCR group, although they achieved a peak at 3 months post-surgery in both groups. Both groups showed improvements in other parameters from 3 months to 1 year post-surgery. Conclusions: Postoperative progression of hyperextension of the first CMC joint was significantly reduced in the ECRL group. The ECRL tendon is thicker than the FCR tendon. In addition, the insertion site of the ECRL tendon is at the dorsal side of the second metacarpal, and the tendon can extend from the dorsal side to the volar side to stabilize the first metacarpal. Thumb CMC arthroplasty using one-half of the ECRL tendon is a useful reconstruction method.

A Validated, Specimen-Specific Finite Element Model of the Supraspinatus Tendon Mechanical Environment.

Rotator cuff tears are a significant clinical problem previously investigated by unvalidated computational models that either use simplified geometry or isotropic elastic material properties to represent the tendon. The objective of this study was to develop an experimentally validated, finite element model of supraspinatus tendon using specimen-specific geometry and inhomogeneous material properties to predict strains in intact supraspinatus tendon at multiple abduction angles. Three-dimensional tendon surface strains were determined at 60 deg, 70 deg, and 90 deg of glenohumeral abduction for articular and bursal surfaces of supraspinatus tendon during cyclic loading (5-200 N, 50 cycles, 20 mm/min) to serve as validation data for computational model predictions. A finite element model was developed using the tendon geometry and inhomogeneous material properties to predict surface strains for loading conditions mimicking experimental loading conditions. Experimental strains were directly compared with computational model predictions to validate the model. Overall, the model successfully predicted magnitudes of strains that were within the experimental repeatability of 3% strain of experimental measures on both surfaces of the tendon. Model predictions and experiments showed the largest strains to be located on the articular surface (∼8% strain) between the middle and the anterior edge of the tendon. Importantly, the reference configuration chosen to calculate strains had a significant effect on strain calculations, and therefore, must be defined with an innovative optimization algorithm. This study establishes a rigorously validated specimen-specific (both geometry and material properties) computational model using novel surface strain measurements for the use in investigating the function of the supraspinatus tendon and to ultimately predict the propagation of supraspinatus tendon tears based on the tendon's mechanical environment.

Proximal Adductor Avulsion: A Biomechanical Comparison of Suture Anchor Repair Techniques

Objectives:Acute avulsion of the proximal fibrocartilaginous origin of the adductor longus (AL) is an injury mostly occurring in individuals that perform cutting and rapid lateral movements such as in hockey, soccer, and rugby. Especially in competitive athletes, recent trends have advocated for surgical repair of these acute injuries. However, while multiple repair configurations have been proposed, the current literature lacks biomechanical data to guide surgical technique. Therefore, the purpose of this study was to determine load-to-failure values for two proximal adductor repair techniques and to compare their strength to that of a native, uninjured proximal adductor tendon.Methods:Seventeen cadaveric fresh frozen pelvic specimens were dissected to preserve the proximal adductor tendon and the fibrocartilage attachment to the pubis. The specimens were then divided into three groups: an intact AL tendon(baseline control), and ‘torn’ tendons repaired with either a 2-suture anchor or 4-suture anchor technique. Once repaired, specimens were cyclically loaded on a custom jig to simulate a maximal effort soccer-style kick. Testing endpoints included suture anchor pull-out, loss of clamp fixation, or catastrophic tendon failure. To control for individual differences, values were reported both in terms of gross force and as load-to-displacement ratios. Following collection, data from each of the three groups were recorded and analyzed via Kruskal-Wallis and multiple comparison tests.Results:The mean load to failure for the 4-anchor group was 83.74±19.28 N, which was significantly greater than for either the intact (25.43±3.46 N, p <0.05) or 2-anchor repair (20.58±1.33 N, p <0.001) conditions. All intact and 4-anchor repair specimens failed via disruption distal to the adductor’s musculotendinous junction, with no failure at the bone-anchor interface noted in either of these groups. In contrast, 80% of 2-anchor repairs failed at the bone to anchor interface. In this group, following initial pullout, failure of a secondary anchor occurred with 41.4% less force than for the index failure (p < 0.001).Conclusion:This study provides biomechanical data which identifies a 4-anchor repair as being much more resistant to surgical-site failure than a 2-anchor construct. Further, the 4-anchor group failed at the same anatomic location as the intact adductor group, suggesting that a 4-anchor construct results in a repair that acts similar to an uninjured control. Based on this finding, a 4-anchor repair construct should be preferentially used in proximal adductor repair whenever clinically feasible.Figure:Images of Adductor Dissection. A) Complete view of pubic symphysis with instrument at midline. B) Red line demonstrating transection of midline to demonstrate bilateral AL insertions. C) Detachment of the proximal adductor longus (yellow star) from its origin along the pubic body.Figure:Adductor Longus Experimental Design prior loading test A) Loaded adductor specimen in materials testing apparatus. B) Close up of two anchor adductor repair within potting medium

Tunneling Away Lateral Ankle Pain

TITLE: Tunneling Away Lateral Ankle Pain AUTHORS: Geoffrey M. Dreher, DO; David Webner, MD; Kevin DuPrey, DO ACSM Sponsor (if you accept): Thomas Kaminski, PhD, ATC ([email protected]) HISTORY: 60-year-old boilermaker presented with 2-month insidious onset left lateral ankle pain, localized to the lateral malleolus, described as achy and throbbing, 7/10, worse with walking, stairs and climbing ladders. No relief with Acetaminophen or NSAIDs. PHYSICAL EXAMINATION: Left ankle: no edema or ecchymosis, full range of motion with pain in active dorsiflexion and plantarflexion. Strength 5/5, gross sensation intact and 2+ dorsalis pedis and posterior tibial pulses. Tenderness to palpation along the lateral malleolus extending distally approximately 5 cm along lateral ankle. DIFFERENTIAL DIAGNOSIS: 1. Chronic lateral ankle instability 2. Peroneal tendinosis with subluxation 3. Lateral malleolar stress fracture 4. Ankle osteoarthritis 5. Talar osteochondral lesion TEST AND RESULTS: •Left ankle 3 view x-ray: Normal. •Left ankle MRI: Anatomic variant involving conjoined peroneus brevis and longus tendons, located along the anterolateral aspect of distal fibula. Deficient/absent peroneal groove along posterior fibula, which also suggests congenital abnormality. Mild conjoined tendinosis, without surrounding edema. •Left lateral ankle ultrasound: Intact peroneal tendon overlying the lateral maleolus with trace fluid in sheath. The peroneal tendons split just before brevis insertion onto base of 5th metatarsal. FINAL/WORKING DIAGNOSIS: 1. Conjoined left peroneal tendon subluxation with tenosynovitis and absence of fibular groove. TREATMENT AND OUTCOMES: 1. Physical therapy for 6 weeks led to improved balance and walking mechanics, but no change in pain. 2. Immobilization in CAM boot for 6 weeks caused no improvement in pain or swelling out of boot. 3. Corticosteroid injection to peroneal tendons at level of lateral malleolus lead to no improvement. 4. Podiatry referral and surgery including tubularization of peroneal tendons, creation of 6mm fibular groove and repair of peroneal retinaculum. 3 months post-operatively, the patient was full weight bearing pain free with daily activities in lace-up ankle brace.

Arthroscopic Repair of Rare Transtendinous Rotator Cuff Tear: Utilizing Established Portals and a Posterior Superior Accessory Portal

There is a high incidence of rotator cuff injuries in the adult population, and there are well-described techniques for the most common types. Full-thickness transtendon rotator cuff tears are an uncommon injury, and there is limited literature on the appropriate treatment. These rare injuries are important to recognize due to the risk of repair failure using traditional techniques. Simply anchoring the medial portion of the tendon to the anatomic footprint after debriding the lateral tendon risks overtensioning the tendon. Previous techniques share the problem of poor visualization and difficulty passing sutures from standard portals. This technique uses 2 portals, the well-described Neviaser portal and a posterior superior accessory portal. Through these 2 portals, the goal is to increase visualization, increase ease of passing sutures, and avoid debridement of intact tendon.

The utility of dual-energy CT collagen material decomposition technique for the visualization of tendon grafts after knee ligament reconstruction

ObjectiveThe purpose of this article is to assess whether dual-energy CT (DECT) collagen material decomposition technique could reliably depict graft integrity in patients with knee ligament reconstruction. MethodsSeventy patients (mean age, 29.8 years; age range, 15–57 years; 61 men, 9 women) who underwent knee DECT, from June 2016 to January 2018, after knee ligament reconstruction were included in our study. A total of 92 intact tendon grafts (autograft, n = 37; allograft, n = 50), confirmed by MRI and clinical assessment or second-look arthroscopy of the operated knee, were evaluated. The type and number of reconstructed ligaments were as follows: anterior cruciate ligament (ACL) (n = 30), posterior cruciate ligament (PCL) (n = 20), medial collateral ligament (MCL) (n = 12), lateral collateral ligament (LCL) (n = 10), posterolateral ligamentous complex (PLC) (n = 7), anterolateral ligament (ALL) (n = 6), and medial patellofemoral ligament (MPFL) (n = 7). All DECT tendon-specific color mapping images were analyzed by two radiologists independently. Each reconstructed ligament was divided into proximal, middle, and distal portion and rated separately using a three-point scale (0 = absent 'dual-energy color staining'; 1 = partial 'dual-energy color staining'; 2 = full 'dual-energy color staining'). ResultsThe mean of total visualization scores of reconstructed ligaments were 5 or more out of 6 points (PCL: 5.0 ± 0.8; MCL: 5.4 ± 0.7; LCL: 5.5 ± 0.5; PLC: 5.4 ± 1.0; ALL: 5.3 ± 0.6; MPFL: 5.8 ± 0.5), except for ACL (4.3 ± 1.7). No significant difference was observed in the mean of total visualization scores between the autografts and allografts (p > 0.05). The frequency of the score 0 was greater than 10% for the ACL group (15.7%), while less than 5% or 0% for the other groups. Overall, substantial to almost perfect interobserver agreement (range 0.71–0.93) was found for all types of ligaments. ConclusionDECT collagen material decomposition technique could be a valuable tool to qualitatively display tendon grafts in the patients with knee ligament reconstruction, but more caution would be needed to assess ACL graft.

An intact subscapularis tendon and compensatory teres minor hypertrophy yield lower failure rates for non-operative treatment of irreparable, massive rotator cuff tears.

To investigate whether subscapularis integrity and compensatory teres, minor hypertrophy is associated with maintaining relatively good function and tolerable pain levels during non-operative treatment. This study included 108 patients with irreparable, massive rotator cuff tears involving at least two tendons and stage III or IV muscle hypotrophy and fatty infiltration on oblique sagittal magnetic resonance imaging, in which even a partial repair does not seem feasible. All supraspinatus and infraspinatus muscles were grade IV; if the subscapularis was involved, only stage III or IV was included. Patients were divided into two groups: group A consisted of 67 patients with both an intact subscapularis and teres minor hypertrophy; group B consisted of 41 patients lacking either one or both. The Visual Analogue Scale pain score, the American Shoulder and Elbow Surgeons score, the University of California at Los Angeles shoulder score, and active range of motion (ROM) were assessed. During the follow-up period, failure of non-operative treatment was found in 29 (43%) patients in group A and 28 (68%) in group B (p = 0.012). Conversion to surgery was noted in 26 (39%) patients in group A and 27 (66%) in group B (p = 0.006). Among the remaining nonsurgical patients, there were no significant differences in clinical outcomes between the groups except ROM in internal rotation at final follow-up. Although conservative treatment was not always successful in patients with irreparable, massive cuff tears, patients with both an intact subscapularis tendon, and teres minor hypertrophy experienced significantly lower incidences of failure and conversion to surgery, since force couple is maintained in the setting of minimal arthritis. III.

Proximal Hamstring Repair: A Biomechanical Analysis of Variable Suture Anchor Constructs

Background:Despite an abundance of literature regarding construct strength for a myriad of anchors and anchor configurations in the shoulder, there remains a paucity of biomechanical studies detailing the efficacy of these implants for proximal hamstring repair.Purpose:To biomechanically evaluate the ultimate failure load and failure mechanism of knotless and knotted anchor configurations for hamstring repair.Study Design:Controlled laboratory study.Methods:A total of 17 cadaveric specimens divided into 3 groups composed of intact hamstring tendons as well as 2 different anchor configurations (all-knotted and all-knotless) underwent first cyclic loading and subsequent maximal loading to failure. This protocol entailed a 10-N preload, followed by 100 cycles incrementally applied from 20 to 200 N at a frequency of 0.5 Hz, and ultimately followed by a load to failure with a loading rate of 33 mm/s. The ultimate failure load and mechanism of failure were recorded for each specimen, as was the maximal displacement of each bone-tendon interface subsequent to maximal loading. Analysis of variance was employed to calculate differences in the maximal load to failure as well as the maximal displacement between the 3 study groups. Holm-Sidak post hoc analysis was applied when necessary.Results:The all-knotless suture anchor construct failed at the highest maximal load of the 3 groups (767.18 ± 93.50 N), including that for the intact tendon group (750.58 ± 172.22 N). There was no statistically significant difference between the all-knotless and intact tendon groups; however, there was a statistically significant difference in load to failure when the all-knotless construct was compared with the all-knotted technique (549.56 ± 20.74 N) (P = .024). The most common mode of failure in both repair groups was at the suture-tendon interface, whereas the intact tendon group most frequently failed via avulsion of the tendon from its insertion site.Conclusion:Under biomechanical laboratory testing conditions, proximal hamstring repair using all-knotless suture anchors outperformed the all-knotted suture anchor configuration with regard to elongation during cyclic loading and maximal load to failure. Failure in the all-knotted repair group was at the suture-tendon interface in most cases, whereas the all-knotless construct failed most frequently at the musculotendinous junction.Clinical Relevance:No biomechanical studies have clearly identified the optimal anchor configuration to avert proximal hamstring repair failure. Delineating this ideal suture anchor construct and its strength compared with an intact hamstring tendon may alter the current standards for postoperative rehabilitation, which remain extremely conservative and onerous for these patients.

The Diagnostic Value of Subscapularis Clinical Tests in the Postoperative Diagnosis of Subscapularis Retears: An Ultrasound-Comparative Trial

Background: Different physical examination tests have been used to preoperatively determine both the presence and size of a primary subscapularis tear. On the contrary, no clinical trial has yet been published to assess the diagnostic validity of the aforementioned tests in diagnosing subscapularis retears after arthroscopic subscapularis repair. Objective: To investigate the diagnostic value of the most commonly used clinical tests in the diagnosis of subscapularis tendon retears after arthroscopic repair. Methods: A retrospective (prospectively collected data) case series involving 37 patients who were suffering from symptomatic complete subscapularis tendon tear was conducted. All patients underwent an all-arthroscopic subscapularis repair with the same operative technique. They were postoperatively evaluated (final end point of follow-up: 12 months) with the use of ultrasound, Constant-Murlay score (CS), bear hug test, internal rotation lag sign, Napoleon test and lift-off test. Sensitivity, specificity, accuracy, positive and negative prognostic values were calculated for each test. Results: Shoulder function was significantly improved according to the final CS. The internal rotation lag sign was the most sensitive for the diagnosis of postoperative subscapularis retears, while the Napoleon sign had the highest specificity. Although postoperative clinical tests yielded no false negative findings, they were poorly predictive as for new ruptures. Ten patients (27%), who were found with a positive (for re-rupture), postoperative, clinical test, had a sonographically intact subscapularis tendon repair. Conclusion: We strongly support the use of subscapularis-specific clinical tests as a composite, in combination with a specific interpretation of their results. If all tests are found negative for retear, then we could assume that the arthroscopic repair remains intact and no further diagnostic examination might be necessary. On the contrary, if at least one subscapularis-specific clinical test is positive for retear, then the patient will likely require additional imaging control for definite diagnosis.

Computerized tomographic prediction of flexor tendon injuries complicating hamate hook fractures.

We reviewed computerized axial tomography of 28 patients with hamate hook fractures who had surgical resection of the hook. We analysed the relationship between the fragment height ratio, fragment gap, and intraoperative findings of the tendons. We determined whether parameters in the images can predict complication of tear or disruption of the flexor tendons to the ring or little fingers. Of 28 patients, 16 had fragment height ratios between 50-74; ten among them had worn (eight patients) or ruptured (two patients) flexor tendons. Nine of the ten patients had fragment gaps greater than 2 mm. The remaining 12 patients had fragment height ratios between 75-100 and had intact tendons. We conclude that a fragment height ratio greater than 75 and fragment gap less than 2 mm in computer tomography may rule out tear or disruption of the flexor tendons of the ring and little fingers after hamate hook fractures, and a fragment height ratio between 50-74 with fragment gap greater than 2 mm indicates a high risk of flexor tendon tear or disruption. Level of evidence: IV.

Clinical and Etiological Spectrum of Hypokalemic Periodic Paralysis in a Tertiary Care Hospital in Pakistan.

IntroductionHypokalemic periodic paralysis (HPP) is characterized by muscle weakness secondary to low serum potassium levels. It may be primary in origin or there may be secondary causes like thyrotoxic periodic paralysis, renal or suprarenal causes, or non-renal causes like gastroenteritis.AimTo study the etiology, clinical manifestations, and outcome after therapy of patients with hypokalemic paralysis.MethodologyThe study was conducted from January 2016 to December 2016. Patients fulfilling the diagnostic criteria for hypokalemic paralysis, i.e., flaccid muscle weakness involving two or more limb muscles due to serum potassium < 3.5 mmol/L and with no objective sensory signs were included in the study. Relevant investigations were done. Those with other causes of flaccid weakness or on diuretic therapy were excluded from the study. Data was analyzed using SPSS Version 20.0 (IBM Corp., Armonk, NY).ResultsIn our study, 14 patients out of a total of 18 (14/18, i.e., 77.78%) were male and 4/18 (22.22%) were female [Male: Female ratio: 3.5:1]. The mean age of onset of HPP in males (29.5±10.14 yrs.) was lesser than that of females (41±10.8 yrs.), but this difference was statistically not significant (p<0.066). In the entire sample there were 15/18 cases (83.33%) of primary and 3/18 (16.67%) cases of secondary HPP [2/3 had thyrotoxic periodic paralysis and 1/3 had gastroenteritis]. Furthermore, 12/18 patients (66.66%) had symmetrical weakness (five cases of paraparesis and all were male; seven cases of quadriparesis: six males and one female) and 6/18 (33.33%) had asymmetrical weakness (two paraparesis: one male, one female; four quadriparesis: two males, two females). Statistically, no significant difference (p<0.709) was seen in those with symmetrical versus those with asymmetrical weakness. In this study 7/18 (38.89%) cases had absent, 1/18 (5.55%) had diminished, and 10/18 (55.55%) cases had intact deep tendon reflexes. None of the cases had cranial, bulbar, or respiratory involvement. The mean serum potassium of sample was 3.18±0.5 standard deviation (SD). The reduction in serum potassium was moderate (2.5-3.5 mmol/L) in primary and severe (<2.5 mmol/L) in secondary HPP. Those with quadriparesis had severe hypokalemia with a mean serum potassium of 2.1 mmol/L. Only 3/18 patients had concomitant magnesium deficiency. Patients given intravenous potassium replacement (except one with moderate hypokalemia and given oral replacement) recovered dramatically. The mean recovery time was 38.6±20.3 hours. The recovery time in quadriparesis was about 24 hours and in paraparesis was 12 hours. Only one patient with thyrotoxic periodic paralysis (TPP) and with severe serum potassium deficiency (0.9 meq/L) died due to cardiac arrhythmia. No atypical presentation was seen.ConclusionHPP has male preponderance. The age of onset of HPP is earlier in males than in females. Moreover, males are more prone to have symmetrical weakness. Asymmetrical weakness has almost an equal gender distribution. Primary hypokalemic paralysis is more frequent than secondary. Thyrotoxic periodic paralysis is the commonest cause of secondary periodic paralysis. The recovery time in quadriparesis is almost double the recovery time in paraparesis. Respiratory involvement is rare. HPP is an important differential in the diagnosis of acute flaccid muscle weakness. It should be promptly addressed to prevent recurrence of paralysis.

EFFECT OF SUBSCAPULARIS TEARS ON FUNCTIONAL SCORES OF PATIENTS UNDERGOING ROTATOR CUFF REPAIR.

ABSTRACTObjective:To evaluate the influence of partial- and full-thickness upper third subscapularis tendon tears on the functional scores of patients undergoing arthroscopic rotator cuff repair.Methods:Patients who underwent arthroscopic rotator cuff repair were divided into three groups according to the subscapularis tendon condition: intact, partial-thickness tear, or full-thickness upper third tear. Functional scores were compared among groups. Second, the influence of biceps and infraspinatus tears on the scores was tested using multivariate regression analysis.Results:We evaluated 307 shoulders in 297 patients. Full-thickness upper third subscapularis tears presented significantly worse scores than intact tendons. Partial-thickness tears had scores that did not differ significantly from those of the other groups. Patients with full-thickness upper third tears presented a greater rate of injured and unstable biceps tendons. The multivariate analysis showed that biceps and infraspinatus tendon tears did not influence the scores or the intergroup comparison.Conclusion:Full-thickness upper third subscapularis tendon tears presented worse functional scores than intact subscapularis tendons among patients undergoing posterosuperior rotator cuff repair. Patients with full-thickness subscapularis tears were more likely to suffer biceps tears, but this fact did not influence functional scores. Level of Evidence I; Clinical randomized trial

The Effects of Corticosteroid Injection in the Healthy and Damaged Achilles Tendon Model: Histopathological and Biomechanical Experimental Study in Rats.

To show the effects of corticosteroids on inflammatory reactions in the injured Achilles tendon in rats. Thirty-two adult Wistar Albino rats were used in the study. The rats were divided into 4 groups. In the first group (Intact Saline), saline solution was injected to the intact Achilles tendon. In the second group (Intact Corticosteroid), corticosteroid was injected to the intact tendon. In the third group (Injured Saline), saline solution was injected to the injured Achilles tendon. In the fourth group (Injured Corticosteroid), corticosteroid was injected to the injured tendon. All groups were sacrificed on day 30 and Achilles tendons were taken and prepared for histological and biomechanical evaluation. According to the biomechanical test; mean load-to-failure of the Intact Saline group was significantly lower than the Intact Corticosteroid (p=0.016), Injured Saline (p=0.001) and Injured Corticosteroid) (p=0.012) groups. According to the histopathological evaluation, tenocyte mean of the Intact Saline group was statistically lower than the Injured Saline and Injured Corticosteroid groups. Tenocyte mean of the Intact Corticosteroid group was statistically significantly lower than the Injured Saline and Injured Corticosteroid groups. The ground substance mean of the Intact Saline group was significantly lower than the Injured Saline and Injured Corticosteroid groups. The ground substance mean of the Intact Corticosteroid group was significantly lower than the Injured Saline and Injured Corticosteroid groups. There was no statistically significant difference between the groups in terms of calcification. It has been found that there is biomechanical and histopathological significant benefit of intra-tendon corticosteroid administration in the experimentally generated Achilles tendon injury model.

Biceps Detachment Preserves Joint Function in a Chronic Massive Rotator Cuff Tear Rat Model

Background: Lesions of the long head of the biceps tendon are often associated with massive rotator cuff tears (MRCTs), and biceps tenotomy is frequently performed for pain relief and functional reservation. However, the efficacy and safety of biceps tenotomy regarding the effects on the surrounding tissues in chronic MRCT are unclear. Hypothesis: Biceps tenotomy would result in improved mechanical and histological properties of the intact subscapularis tendon and improved in vivo shoulder function while not compromising glenoid cartilage properties. Study Design: Controlled laboratory study. Methods: Right supraspinatus and infraspinatus tendons were detached in 25 male Sprague-Dawley rats, followed by 4 weeks of cage activity to create a chronic MRCT condition. Animals were randomly divided into 2 groups and received either biceps tenotomy (n = 11) or sham surgery (n = 14) and were sacrificed 4 weeks thereafter. Forelimb gait and ground-reaction forces were recorded 1 day before the tendon detachment (baseline), 1 day before the surgical intervention (biceps tenotomy or sham), and 3, 7, 10, 14, 21, and 28 days after the intervention to assess in vivo shoulder joint function. The subscapularis tendon and glenoid cartilage were randomly allocated for mechanical testing or histologic assessment after the sacrifice. Results: Compared with sham surgery, biceps tenotomy partially restored the in vivo shoulder joint function, with several gait and ground-reaction force parameters returning closer to preinjury baseline values at 4 weeks. With biceps tenotomy, mechanical properties of the subscapularis tendons were improved, while mechanical properties and histological Mankin scores of the glenoid cartilage were not diminished when compared with the sham group. Conclusion: Biceps tenotomy in the presence of chronic MRCT partially preserves overall shoulder function and potentially restores subscapularis tendon health without causing detrimental effects to joint cartilage. This laboratory study adds to the growing literature regarding the protective effects of biceps tenotomy on the shoulder joint in a chronic MRCT model. Clinical Relevance: This study provides important basic science evidence supporting the use of biceps tenotomy in patients with massive rotator cuff tears.

Superior Capsular Reconstruction Reverses Profound Pseudoparalysis in Patients With Irreparable Rotator Cuff Tears and Minimal or No Glenohumeral Arthritis

The purpose of the study was to investigate the rate and magnitude of return of active forward elevation (aFE) of the arm for patients with severe preoperative elevation dysfunction (less than 45° of aFE and termed profound pseudoparalysis) and massive, irreparable (or partially reparable) rotator cuff tears without arthritis treated with arthroscopic superior capsular reconstruction (SCR). The period for this retrospective study was October 2014 to October 2016. Inclusion criteria included patients treated arthroscopically for an incompletely reparable massive rotator cuff tear (2 tendons fully torn or tear dimension > 5cm), preoperative aFE of less than 45° (profound pseudoparalysis) with full passive elevation, an intact or reparable subscapularis tendon, radiographic classification Hamada 0-3, and 12-month clinical follow-up. The primary outcome measure was aFE (degrees) at 1year postoperative. Secondary outcomes included visual analog scale pain rating (0-10), American Shoulder and Elbow Surgeons score, subjective shoulder value, and active external rotation. Graft integrity and Goutallier grade of supraspinatus and infraspinatus at 1year postoperative were evaluated by magnetic resonance imaging. Ten patients met the inclusion criteria. Nine of 10 patients (90%) regained active overhead use of the arm after SCR with preoperative aFE (mean ± standard error of the mean [95% confidence interval (CI)]) 27° ± 2° [95% CI, 24°-30°] improving to postoperative aFE 159° ± 15° [95% CI, 130°-187°; P < .0001]. All secondary outcome measures were also improved at 1year postoperative (visual analog scale, 4.6 ± 0.8 to 0.5 ± 0.2; P= .001; American Shoulder and Elbow Surgeons, 52 ± 6 to 89 ± 3; P= .0002; subjective shoulder value, 36 ± 3 to 91 ± 1; P < .0001; active external rotation, 24° ± 7° to 43° ± 8°; P= .002), and 7 of 10 SCR grafts were fully healed by MRI. No complications or reoperations occurred. Profound pseudoparalysis of the shoulder (active elevation less than 45°) in massive, irreparable rotator cuff tears without arthritis was reversed in 90% of patients after arthroscopic SCR. Reverse shoulder replacement has been proposed to be the only reliable surgical option in this patient group, but SCR appears to be a valid joint-preserving option for improving function with a low rate of complications. Level IV, therapeutic case series.

Diagnostic Accuracy of the Scapular Retraction Test in Assessing the Status of the Rotator Cuff.

Background:Currently, clinical physical examination maneuvers alone provide variable reliability in diagnosing full-thickness rotator cuff tears (RCTs).Purpose:To assess the diagnostic accuracy of the scapular retraction test (SRT) to predict full-thickness RCTs.Study Design:Cohort study (diagnosis); Level of evidence, 2.Methods:A total of 331 patients were prospectively evaluated in this cohort study. SRT was performed to assess the status of the rotator cuff. A positive SRT indicates an intact rotator cuff, and a negative SRT indicates a full-thickness RCT. Magnetic resonance imaging (MRI) was used as the gold standard. The examiner was blinded to the results until completing the physical examination. Statistical analysis was performed to assess the sensitivity, specificity, accuracy, positive and negative predictive values, and positive and negative likelihood ratios of the SRT.Results:The prevalence of full-thickness RCTs diagnosed on MRI was 54.4% (180 of 331). Among the 180 patients with an MRI-confirmed full-thickness RCT, the SRT was negative for 147. Of 150 patients with an intact rotator cuff by MRI, 122 had a positive SRT. In diagnosing full-thickness RCTs, the SRT had a sensitivity of 81.7% (95% CI, 77.2%-85.4%), specificity of 80.8% (95% CI, 75.5%-85.3%), and accuracy 81.3%. The positive predictive value was 83.5% (95% CI, 78.9%-87.4%); the negative predictive value, 78.7% (95% CI, 73.5%-83.1%); the positive likelihood ratio, 4.3 (95% CI, 3.1-5.8); the negative likelihood ratio, 0.23 (95% CI, 0.17-0.30); and the diagnostic odds ratio, 18.7 (95% CI, 10.4-34.0).Conclusion:The results of this diagnostic study indicate that the SRT can accurately be used to clinically assess the status of the rotator cuff. This physical examination maneuver was found to be accurate, sensitive, and specific in diagnosing full-thickness RCTs. Additionally, our results indicate that it is equally as accurate to predict an intact rotator cuff tendon. Providing an accurate, reliable, and reproducible physical examination test will allow clinicians to diagnosis the integrity of the rotator cuff and will help guide treatment recommendations.

Effects of supercritical fluid CO2 and 25kGy gamma irradiation on the initial mechanical properties and histological appearance of tendon allograft.

Tendon allografts, when autograft options are limited or when obtaining an autograft is not aligned with the patients' best interest, play an important role in tendon and ligament reconstruction. To minimize the risk of infectious disease transmission tissue banks perform screening tests and the allografts cleaned are sterilized. The current study examines and compares the initial mechanical properties and histological appearance of supercritical CO2 (SCCO2)-treated and gamma-irradiated porcine extensor tendons. Thirty intact porcine forelimb extensor tendons randomized equally into three groups: control group, gamma-irradiation group, and SCCO2-treated group. Once treated, histological assessment and histomorphologic measurements were made on the histological sections obtained from each tendon while stiffness and ultimate failure loads were evaluated from tensile testing. Histological evaluation of gamma-irradiated tendons showed significant disruption to the hierarchical morphology of the fascicle bundles, which was not evident in SCCO2-treated specimens. Histomorphologic measurements showed a significant increase for measured dead space (void) between tendon fibrils of the gamma-irradiated group comparing to both control and SCCO2 treated groups (p < 0.01). There was a significant reduction in the ultimate failure load for tendons treated by gamma-irradiation compared to the control group (p < 0.05). No statistically significant difference was detected between control and SCCO2-treated tendons in the ultimate failure load. Stiffness values were not significantly different between three-study groups. This study suggests that while gamma-irradiation has a deleterious effect on mechanical properties of tendon tissue, SCCO2 does not alter the biomechanical properties and the histological structure of porcine extensor tendons.